Pliska was the first Capital (after 681-893) of the First Bulgarian Kingdom. Its ruins lie 3 km north of today's village of Pliska (prev. name Aboba). Its name was mentioned in many resources most si-gnificant of which are the Bulgarian apocryphal chronicle from XIc. AD as the town of Plyuska founded by Asparuh Khan, the
Byzantine authors George Cedrin,John Zonara, Anna Komnina asPliskusa. The town had area of 23 km2 and was surrounded by 21 km long defensive line built up of moat and rampart. The Inner town had area of 0.5 km2 rectangular shape and had 2.6 m thick and about 12 m high fortress
walls, cylindrical towers at each corner, and two other towers at each wall.

In the Inner town there was situated the Big palace (Khan Kroum's palace) which has it's own defensive walls and towers and the so called Palace centre which formed the third defensive line of the town. With its great size and advanced fortification system Pliska was a remarkable state centre in the early medieval ages.